Multi-layered steel gaskets are traditionally used to form a seal between two mating components of a mechanical system or device, such as an internal combustion engine, to prevent leakage of combustion gases, cooling water, lubricating oil, or the like. Common applications involve placing a multi-layered steel gasket assembly between the engine block and cylinder head and between the engine block and exhaust manifold. Cylinder head gaskets typically extend around the cylinder bores of an engine to seal high-pressure combustion gases within the cylinder bores as well as seal oil and coolant passages. Exhaust manifold gaskets typically extend around the exhaust ports of an engine to seal high temperature exhaust gases flowing into the exhaust system. Once installed, the multi-layered steel gasket assembly bears the load from a bolted connection of the engine components and relies upon this load to provide an adequate seal therebetween.
Often, in the manufacture of multi-layered steel gaskets, at least one coating layer is disposed between a plurality of steel gasket layers to form a gasket assembly, such that the sealing ports defined by the gasket assembly are concentric. The coating layers are substantially coextensive with the plurality of steel gasket layers.
Often, the material selected for the coating layers has inherent an electrical insulating properties. Thus, the coating layers may have an electrical resistance substantially greater than that of the steel gasket layers, electrically insulating the plurality of steel gasket layers from each other. As such, the possibility of using resistance welding as the means of joining the plurality of steel gasket layers together is not feasible. In such cases, it is a common to secure the coated gasket layers together by means of rivets or eyelets. While effective, the use of rivets or eyelets add to the cost and complexity of manufacturing gaskets.